We demonstrated high spectral efficiency real-time 500-Gb/s/carrier transmission over a 1200 km length with terrestrial field-installed cut-off shifted fiber (CSF) of ITU-T G.654.E compliant. For that demonstration, we used our real-time transponder and a combination of three amplification schemes (erbium-doped fiber amplifier (EDFA), and forward and backward distributed Raman amplifiers (DRAs)) that met safety requirements for lasers as defined by safety standard IEC 60825-2. By using forward DRA, optical signal-to-noise ratio (OSNR) improved by more than 1.3 dB. 66-GBaud polarization division multiplexing (PDM) 32 quadrature amplitude modulation (QAM) signals were generated by a real-time transponder using a 16-nm digital signal processing application-specific integrated circuit (DSP-ASIC) with device imperfection compensation technologies. We compared the 500-Gb/s/carrier transmission characteristics in a wavelength-division multiplexing (WDM) condition yielded by CSF, standard single-mode fiber (SMF), and dispersion-shifted fiber (DSF) installed in the field. The results show that the best transmission characteristics are attained by CSF transmission with forward DRA. The 1234-km transmission achieved with high spectral efficiency of 5.71 b/s/Hz, is, as far as we know, the longest yet achieved in 500-Gb/s/carrier transmission field experiments.

中文翻译：

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现场安装的光纤上的高频谱效率实时500-Gb / s /载波长距离传输

我们通过符合ITU-T G.654.​​E标准的地面现场安装的截止移位光纤（CSF），展示了在1200 km长度上的高频谱效率实时500-Gb / s /载波传输。在该演示中，我们使用了实时应答器以及满足安全标准所定义的激光器安全要求的三种放大方案（掺b光纤放大器（EDFA）以及前向和后向分布式拉曼放大器（DRA））的组合IEC 60825-2。通过使用前向DRA，光信噪比（OSNR）提高了1.3 dB以上。实时应答器使用具有设备缺陷补偿技术的16 nm数字信号处理专用集成电路（DSP-ASIC），通过实时应答器生成66 GBaud偏振分复用（PDM）32个正交幅度调制（QAM）信号。我们在现场安装的CSF，标准单模光纤（SMF）和色散位移光纤（DSF）产生的波分复用（WDM）条件下，比较了500 Gb / s /载波的传输特性。结果表明，采用正向DRA的CSF传输可获得最佳的传输特性。据我们所知，在5.7 km / s / Hz的高频谱效率下实现的1234 km传输是500 Gb / s /载波传输现场实验中最长的。